Photocatalytic Activities of Coating Films Prepared from Peroxotitanic Acid Solution-Derived Anatase Sols

Abstract

Anatase sols were prepared from peroxotitanic acid solution by heating at 100 for 2-20h. The sols con sisted of fine anatase particles of diameters less than 20nm and arrowhead-like particles larger than 20nm. The sols heated for 2-6h dispersed well, whereas the sols heated for 8-20h tended to aggregate. The powders obtained by drying the sols had high specific surface areas of 180 to 245m2g-1. On photocatalytic degradation of a commercial vegetable oil on films prepared from the sols, the weight loss was approximated by the zero-order kinetics on the oil concentration at the early stage of the degradation. The film prepared from the sol heated for 6h showed a highest rate constant of 1.6810-5gcm-2h-1 under ultraviolet light ir radiation at 1.4mWcm-2.

Synthesis of Titania Particles by Low-Temperature Hydrolysis Reaction of Titanium Alkoxide and Their Surface Properties

“…First, 100 cm 3 of distilled water whose temperature was adjusted to the reaction temperature was added to 0.01 mol of titanium tetraisopropoxide Ti O-iPr 4 TIP in a 200 cm 3 Pyrex glass beaker. The molar ratio of H 2 OTIP was 555.6.…”

Immobilization of highly active titanium(IV) oxide particles

“…Through this technique, TiO 2 films of high photocatalytic activity were produced [6][7][8]. Preparation of TiO 2 films from crystalline colloidal TiO 2 solution were also reported [9][10][11] and recently TiO 2 thin films of high photocatalytic activity were obtained from a TiO 2 sol prepared by hydrothermal treatment of peroxotitanic acid solution [12,13] or an alkoxide-derived TiO 2 gel [14].…”

Comparative examination of titania nanocrystals synthesized by peroxo titanic acid approach from different precursors

“…It is well known that the metastable anatasetype TiO 2 exhibits excellent photocatalytic activity among the three polymorphs of anatase, rutile, and brookite. Pure anatase titania can be prepared by the ordinary sol-gel method [6][7][8][9][10] or recently by the peroxo titanic acid (PTA) approach [11][12][13][14]. The sol-gel method using alkoxide precursors is a popular and effective way to obtain anatase particles because of easy hydrolyzing properties of alkoxide.…”

“…are usually applied as precursors in the PTA approach [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26]. However, anatase products obtained from these precursors easily contain impurities such as NH + 4 (from the neutralization agents, NH 4 OH) or the peroxo group -O-O- [11].…”